What is it and how do I get rid of it?

Reactivity is a broad term used by dog trainers to describe an over aroused reaction to unfamiliar people, dogs and/or things in the dog’s environment.  If you think about it, dogs are reacting to their environment all the time, so really everything is reactivity.  But in this case we are talking about a particular picture that looks like …lunging, barking, snapping, growling and threatening someone or something in the dog’s environment, usually when the dog is on the end of a leash or restrained in some way.  In all cases, reactivity is a dog’s emotional response to something in his/her environment.  The two most common emotions behind aggression in dogs is fear and/or guarding  of resources.

Let’s take the example of the dog who displays aggression when a stranger enters your house or approaches you on the street.  When the dog perceives the stranger a fear response is triggered in the dog’s brain.  That fear is usually accompanied by guarding behavior which is the dog saying to the world, “All of this and these people are mine…stay away!!”

The part of the brain responsible for these types of warning systems is the “old brain”.  The “old brain” is responsible for survival.  The dog doesn’t think about their reaction, their body just does it because ……their “old brain” told it to.  THe dog believes that this is exactly the right thing to be doing at this particular moment.

Many people report that their dog does not listen or respond to them when they are in a reactive state.  The simple reason for this is that they can’t!  For the dog to respond to you they would have to be working off of their “new brain” or their frontal cortex.  Physically, the two parts of the brain cannot be accessed at the same time.  It’s one or the other.

Here is a human example that might make this more clear.  Say you are driving in Boston traffic at rush hour (sigh).  You are hyper aware of the situation you are in and trying hard to watch this car and that car, in attempt to survive and get to where you are going safely.  What if, while you are driving someone said to you, “Ok, just keep driving and work on your Phd dissertation at the same time.”  You could not do it.  You would have to pull over, stop everything take many deep breathes and wait until you could focus your brain.  This is kind of what happens to dogs when they are in a reactive state.  They literally can’t think!


Most reactive behavior in dogs is modified by “counter conditioning” the behavior.  Counter Conditioning is exactly what it sounds like,  changing an existing emotion to its counter emotion or opposite.

Enter the CR!!  The Conditioned Reinforcer is the back bone of modern dog training.  It is also called a Mark or a Marker.   In dog training a CR is a signal of some sort that is connected to something highly desirable to the dog…usually food.

How do we establish a CR?  Pretty darn easily.  Most trainers use clickers for their marker.  It is a unique sound that dogs don’t hear in their day to day lives.  Activate the clicker “CLICK” and drop a treat on the floor.  Repeat that about twenty times.  The sound of the click becomes paired with the food.  The sound is a predictor of food and becomes almost as valuable as the food itself.  When the dog hears the sound of the clicker his/her brain says “FOOD”!

Back to the reactive behavior.  Now that we have an established CR (click) we can attach that very same sound to the appearance of the scary trigger and eventually change the dog’s emotional response to the stranger from “DANGER,  DANGER” to “CHICKEN, STEAK AND LIVER!” It’s a beautiful thing.

Every dog is different and often changing reactive behavior involves desensitization and functional reinforcement work as well but for the most part, Counter Conditioning is the place to start.

Whenever possible, I like to put a solid foundation of training under a reactive dog before beginning counter conditioning work.  In my experience, this predicts a better outcome over the long run. Dogs who have this history of training are more confident and their handlers have a deeper set of skills to draw from.

If you would like to start changing your dog’s reactivity just click on the button below.  Let’s talk!